Surface-emitting laser having lateral current injection

Abstract

The invention describes a surface-emitting laser (VCSEL) with lateral current injection. The pump current ( 4 ), from the contact face ( 2 ) on the decoupling side, in a first region ( 12 ) outside the resonator volume, is carried predominantly parallel to the resonator axis, and in a second region ( 13 ) is conducted predominantly perpendicularly to the active volume ( 9 ). A contact geometry is also described, which brings about automatic regulation of the size of the active volume ( 9 ) as a function of the pump current ( 4 ).

What is claimed is:  
     
       1. A VCSEL having a semiconductor body ( 1 ), which has a resonator volume, with a resonator axis, an active layer ( 8 ) that includes an active volume ( 9 ) that generates a radiation ( 7 ), and a first and second primary face, a first contact face ( 2 ) being formed on the first primary face and a second contact face ( 3 ) being formed on the second primary face, and in which the generated radiation ( 7 ) is decoupled at least in part through the first primary face, 
       characterized in that  
       the pump current ( 4 ) in a first region ( 12 ) is guided from the first primary face to the active layer ( 8 ), outside the resonator volume, predominantly parallel to the resonator axis; and that in a second region ( 13 ), the pump current ( 4 ) is carried to the active volume ( 9 ) predominantly perpendicular to the resonator axis, and an insulation layer ( 11 ) is embodied between the first region ( 12 ) and the resonator volume.  
     
     
       2. The VCSEL of  claim 1 , 
       characterized in that  
       between the second region ( 13 ) and the active layer ( 8 ), a current-constriction layer ( 10 ) is embodied.  
     
     
       3. The VCSEL of  claim 2 , 
       characterized in that  
       the current-constriction layer ( 10 ) has an aperture which, viewed along the resonator axis, at least partly overlaps the active volume ( 9 ).  
     
     
       4. The VCSEL of  claim 2 , 
       characterized in that  
       the current-constriction layer ( 10 ) is formed by ion implantation.  
     
     
       5. The VCSEL of  claim 2 , 
       characterized in that  
       the current-constriction layer ( 10 ) is an annular oxide layer.  
     
     
       6. The VCSEL of  claim 1 , 
       characterized in that  
       the insulation layer ( 11 ) is formed by ion implantation.  
     
     
       7. The VCSEL of  claim 1 , 
       characterized in that  
       the insulation layer ( 11 ) is formed by means of an etched trench.  
     
     
       8. The VCSEL of  claim 7 , 
       characterized in that  
       the etched trench is filled with an insulation or absorber material.  
     
     
       9. The VCSEL of  claim 1 , 
       characterized in that  
       the contact face ( 2 ) is formed annularly, and the generated radiation ( 7 ) exits through the annular opening.  
     
     
       10. The VCSEL of  claim 1 , 
       characterized in that the first contact face ( 2 ) is formed annularly, and the ring is not closed.  
     
     
       11. The VCSEL of  claim 1 , 
       characterized in that  
       the first contact face ( 2 ) is embodied as U-shaped.  
     
     
       12. The VCSEL of  claim 1 , 
       characterized in that  
       the first contact face ( 2 ) is embodied as V-shaped.  
     
     
       13. The VCSEL of  claim 1 , 
       characterized in that  
       the insulation layer ( 11 ) has a lateral cross section which corresponds to the shape of the contact face ( 2 ).  
     
     
       14. The VCSEL of  claim 1 , 
       characterized in that  
       the contact face ( 2 ) is shaped such that with an increasing pump current ( 4 ), the lateral cross-sectional face of the active volume ( 9 ) remains the same or increases.